1. Technical Field
The present invention relates to an optical device and an image display device.
2. Related Art
In order to make the resolution of a projected image higher than the resolution of a light modulation device, such as a liquid crystal panel, a technique for shifting the axis of image light emitted from the light modulation device has been known. In addition, as a device for shifting the axis of image light, an optical path control device disclosed in JP-A-2011-158589 is known. The optical path control device disclosed in JP-A-2011-158589 includes a glass plate, a movable section for holding the glass plate, a support section for supporting the movable section, and a pair of leaf springs for connecting the support section and the movable section to each other. By changing the position of the glass plate by rotating the movable section using the leaf springs as a rotary axis, light (image light) incident on the glass plate is refracted to shift the axis. In the optical path control device disclosed in JP-A-2011-158589, electromagnetic driving using a coil and a permanent magnet is adopted for a driving mechanism for rotating the movable section.
In the optical path control device disclosed in JP-A-2011-158589, however, a yoke is used to guide the magnetic field generated by the coil, and the yoke protrudes up and down. Accordingly, there is a problem in that the device becomes large in size by the amount of protrusion.